Hose assemblies are used for a variety of applications such as hose assemblies for automotive brake lines and fuel lines as well as various non-automotive uses such as water delivery. The hose should be strong, durable and resistant to heat, chemical degradation, and high pressures. When hoses are used to carry organic fluids and vapor, as in fuel lines, the hose should be resistant to permeation by hydrocarbons contained in the fluids so transported. In order to be effective, fluid transport hoses should also be flexible and resistant to crushing, kinking or other events which can reduce cross-sectional area of the hose thereby blocking flow and creating localized areas of high stress within the hose as well as weak points in the hose which subsequently can leak.
Some hoses for fuel and vapor applications in motor vehicles have been multilayered tubes. Typically, hoses for high pressure applications are composed of fiber reinforced thermosetting plastic or rubber materials containing steel fibers, glass fibers or plastic fibers. Other reinforcement mechanisms include using fibers woven or braided around an inner tube. Production of reinforced braided hoses is complex and expensive. Additionally, braid-reinforced rubber hoses generally are not recyclable due to the cross-linking properties of the rubber materials employed.
The current multilayered tubing technology offers excellent low permeation tubes. Different plastic materials can either be extruded together or separately formed in a multilayered structured hose. However, such tubes typically lack necessary properties for high pressure applications such as kink resistance and the like. Heretofore, reinforcement of multi-layered polymeric tubes has been problematic. Coextrusion methods are difficult to apply over or around woven or braided reinforcement materials in a manner which will assure the necessary layer-to-layer integration required for optimum tubing function and structure.
It would be desirable to provide a reinforced tubing structure which is composed of materials which could be easily integrated into the multi-layer structure. Additionally, it would be desirable to provide a reinforced tube having a reinforcement layer which is amenable to various recycling processes when the tube is scraped or discarded. It is also desirable to provide a multi-layer tube having a reinforcement layer which can function as a suitable barrier to prevent hydrocarbon permeation through the tube. Finally, it is desirable to provide a reinforcement layer which permits a significant retention of the characteristics of the various polymeric layers, such as flexibility, electrostatic dissipation and the like.